#!/bin/bash

choice=$1
case $choice in
	time | date) echo "The time is `date`.";;
	dir | path) echo "Current directory is `pwd`.";;
	*) echo "bad argument.";;
esac

#case  语句的值是整个结构中最后执行的那个命令的推出值。若没有执行任何命令,则退出值为0.